Selected ATcT [1, 2] enthalpy of formation based on version 1.202 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.176 in order to include species related to the thermochemistry of glycine[4].

Ketene cation

Formula: [CH2CO]+ (g)

CAS RN: 64999-16-2

ATcT ID: 64999-16-2*0

SMILES: C=C=[O+]

InChI: InChI=1S/C2H2O/c1-2-3/h1H2/q+1

InChIKey: UJTMLNARSPORHR-UHFFFAOYSA-N

Hills Formula: C2H2O1+

2D Image:

Aliases: [CH2CO]+; Ketene cation; Ketene ion (1+); Ethenone cation; Ethenone (1+); CH2CO+; [H2CCO]+; H2CCO+

Relative Molecular Mass: 42.0361 ± 0.0016

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
882.24	879.07	± 0.11	kJ/mol

3D Image of [CH2CO]+ (g)

spin ON spin OFF

Top contributors to the provenance of Δ_fH° of [CH2CO]+ (g)

The 20 contributors listed below account only for 52.2% of the provenance of Δ_fH° of [CH2CO]+ (g).
A total of 270 contributors would be needed to account for 90% of the provenance.

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
11.0	2425.1	CH2 (g, triplet) → CH2 (g, singlet)	Δ_rH°(0 K) = 3147 ± 5 cm-1	Jensen 1988, Jacox 1994
6.3	2413.9	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.80 ± 0.06 kcal/mol	Feller 2016, note unc2
5.0	2286.9	C (graphite) + CO2 (g) → 2 CO (g)	Δ_rG°(1165 K) = -33.545 ± 0.058 kJ/mol	Smith 1946, note COf, 3rd Law
4.6	2413.8	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.76 ± 0.07 kcal/mol	Feller 2014
3.9	2431.1	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 109.26 ± 0.08 kcal/mol	Feller 2016, est unc, note unc2
2.4	2376.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
2.2	2455.8	CH2 (g, triplet) → CH (g) + H (g)	Δ_rH°(0 K) = 418.04 ± 0.35 kJ/mol	Csaszar 2003
2.0	2456.5	CH2 (g, singlet) → CH (g) + H (g)	Δ_rH°(0 K) = 90.97 ± 0.12 kcal/mol	Feller 2014
1.5	2415.9	CH2 (g, singlet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 170.98 ± 0.11 (×1.445) kcal/mol	Feller 2014
1.4	2430.8	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 457.05 ± 0.56 kJ/mol	Harding 2008
1.3	2961.1	CH3OH (g) → CH2 (g, singlet) + H2O (g)	Δ_rH°(0 K) = 90.84 ± 0.17 kcal/mol	Nguyen 2015a
1.3	2428.1	CH3 (g) → [CH2]+ (g) + H (g)	Δ_rH°(0 K) = 15.120 ± 0.006 eV	Litorja 1998
1.2	2412.9	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 752.45 ± 0.56 kJ/mol	Harding 2008
1.2	2425.4	CH2 (g, triplet) → CH2 (g, singlet)	Δ_rH°(0 K) = 3156 ± 15 cm-1	Bunker 1986, note CH2
1.1	2228.7	C (graphite) + O2 (g) → CO2 (g)	Δ_rH°(298.15 K) = -393.464 ± 0.024 kJ/mol	Hawtin 1966, note CO2e
1.1	2430.4	CH3 (g) → CH2 (g, triplet) + H (g)	Δ_rH°(0 K) = 109.22 ± 0.15 kcal/mol	Karton 2008
1.0	2435.1	[CH2]- (g) → C- (g) + 2 H (g)	Δ_rH°(0 K) = 165.69 ± 0.12 kcal/mol	Feller 2016, note unc2
1.0	2412.5	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 179.86 ± 0.15 kcal/mol	Karton 2008
0.9	2415.7	CH2 (g, singlet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 170.80 ± 0.2 kcal/mol	Feller 2008
0.9	2413.1	CH2 (g, triplet) → C (g) + 2 H (g)	Δ_rH°(0 K) = 753.03 ± 0.62 (×1.044) kJ/mol	Csaszar 2003

Top 10 species with enthalpies of formation correlated to the Δ_fH° of [CH2CO]+ (g)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation Coefficent (%)	Species Name	Formula	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
99.7	Ketene	CH2CO (g)	-45.33	-48.39	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*0
99.7	Ketene	CH2CO (g, singlet)	-45.33	-48.39	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*2
99.7	Ketene	CH2CO (g, para singlet)	-45.33	-48.39	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*21
99.7	Ketene	CH2CO (g, ortho singlet)	-45.22	-48.39	± 0.11	kJ/mol	42.0367 ± 0.0016	463-51-4*22
96.8	Methylene	CH2 (g, singlet)	428.74	429.15	± 0.11	kJ/mol	14.02658 ± 0.00081	2465-56-7*2
84.2	Methylene	CH2 (g)	391.076	391.622	± 0.094	kJ/mol	14.02658 ± 0.00081	2465-56-7*0
84.2	Methylene	CH2 (g, triplet)	391.076	391.622	± 0.094	kJ/mol	14.02658 ± 0.00081	2465-56-7*1
78.7	Methyliumyl	[CH2]+ (g)	1393.21	1394.07	± 0.10	kJ/mol	14.02603 ± 0.00081	15091-72-2*0
38.4	Carbon	C (g)	711.393	716.878	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*0
38.4	Carbon	C (g, triplet)	711.393	716.878	± 0.040	kJ/mol	12.01070 ± 0.00080	7440-44-0*1

Most Influential reactions involving [CH2CO]+ (g)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
0.890	4357.1	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 77538.7 ± 0.7 cm-1	Willitsch 2002a
0.109	4357.2	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 77539.4 ± 2.0 cm-1	Wang 2002a
0.000	4360.8	[CH2CO]+ (g) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 291.68 ± 1.50 kcal/mol	Ruscic W1RO
0.000	4360.4	[CH2CO]+ (g) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 292.02 ± 1.60 kcal/mol	Ruscic G4
0.000	4360.7	[CH2CO]+ (g) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 292.22 ± 1.60 kcal/mol	Ruscic CBS-n
0.000	4357.3	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.619 ± 0.003 (×1.834) eV	Niu 1993a, Niu 1993b
0.000	4360.3	[CH2CO]+ (g) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 292.48 ± 1.72 kcal/mol	Ruscic G3X
0.000	4360.6	[CH2CO]+ (g) → 2 C (g) + 2 H (g) + O (g)	Δ_rH°(0 K) = 291.26 ± 2.16 kcal/mol	Ruscic CBS-n
0.000	4357.8	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.614 ± 0.008 eV	Vogt 1978
0.000	4357.7	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.61 ± 0.02 eV	Vogt 1978
0.000	4357.6	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.63 ± 0.02 eV	Hall 1977
0.000	4357.4	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.605 ± 0.02 eV	Price 1951
0.000	4358.8	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.616 ± 0.040 eV	Ruscic W1RO
0.000	4357.5	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.64 ± 0.05 eV	Baker 1969, est unc
0.000	4358.4	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.591 ± 0.073 eV	Ruscic G4
0.000	4358.7	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.599 ± 0.075 eV	Ruscic CBS-n
0.000	4358.3	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.603 ± 0.093 eV	Ruscic G3X
0.000	4358.6	CH2CO (g) → [CH2CO]+ (g)	Δ_rH°(0 K) = 9.624 ± 0.099 eV	Ruscic CBS-n

References

1		B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner, Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2		B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner, Active Thermochemical Tables: Thermochemistry for the 21^st Century. J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3		B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.202 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		B. Ruscic and D. H. Bross Accurate and Reliable Thermochemistry by Data Analysis of Complex Thermochemical Networks using Active Thermochemical Tables: The Case of Glycine Thermochemistry Faraday Discuss. (in press) (2024) [DOI: 10.1039/D4FD00110A]
5		B. Ruscic, Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables. Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
6		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [5] and Ruscic and Bross[6]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.000₅ kJ/mol.

Website Functionality Credits

The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

Acknowledgement

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.